You had to look closely to find the signature, grouped among a number of others at the bottom of a Virginia Military Institute diploma: “T.J. Jackson, Prof.”

“See?” said Paul Davis, pointing to a slight smudge just above Jackson’s name. “It looks like he started to sign on the wrong line and had to move down.”

And when the man who later became famous as Stonewall Jackson applied his pen to that sheet of paper in 1860, he could not have imagined that one day it would be fed into a time machine that would catapult it into the 21st century.